For example, awful once meant, and in fact is still defined in my dictionary (among other definitions) as filling one with terror or dread or worthy of solomn respect. Most contemporary use of the word, however, is in a much more trivial framework, as in "that was an awful cup of coffee."
Mary Poppins' word supercalifragilisticexpialidocious will probably soon mean not bad.
The word "Hero" is lost and there is no substitute. "Hero" has come to mean anyone we like, leaving no word for TRUE Heros. Thus, there is no ability in English to differentiate and discern.
This is true for many other words such as "Impact" and "Overview."